BigPatents India

A process for the production of magnesium alloy strip, by twin roll casting, includes the steps of passing molten alloy from a source of supply to a feeding device; feeding the alloy from the feeding device through an elongate outlet of a nozzle and a pair of substantially parallel rolls spaced to define a bite there between; rotating said rolls whereby alloy is drawn from the chamber through the bite; and flowing coolant fluid through each roll and thereby cool alloy received in the chamber by heat energy extraction by the rolls whereby substantially complete solidification of the alloy is achieved in the chamber prior to alloy passing through the bite as hot rolled alloy strip. Alloy is held at the source at a temperature sufficient to maintain alloy in the feed device at a superheated temperature; a depth of molten alloy is maintained in the feed device at from about 5mm to about 22mm above a centerline of the bite in a plane containing the axes of the rolls; and heat energy extraction by the cooled rolls is maintained at a level sufficient to maintain alloy strip issuing from the bite at a surface temperature below about 400°C; whereby the hot rolled alloy strip is substantially free of cracks and has good surface quality. (FIG. - 9)